Stocking ideas for my brackish tank

[fishb0ne]

It is a standard 10 gallon tank with about 5 gallons of water.
Water is kept at around 74-78*F, gravity between 1.005 and 1.007
Sand substrate, filtered. Plant is fake but I might get some real ones soon.
I have a red clawed crab in there which is doing great, she recently moulted.
But the tank is kinda quiet. I'd like to get something else for it, is that possible? I realize the low water level might be an issue and also the water current at the one end of the tank. Is there a fish, shrimp, anything out there that might be happy in it?
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[STARFYRE]

There are some smaller brackish fish that would be suitable for a 10 gal tank. I've kept bumblebee gobies and mini puffers. Both get no bigger than 2 inches. If you keep them together, the puffers will probably bite at the gobies. The crab may also snack on them (I'm not familiar with that type of crab's behavior). The puffers will probably hold thier ground with the crab, but they might eat him. Compatability can be a problem here. I'm not sure if there's any other type of brakish fish that would be small enough for a ten gallon. I did keep a figure 8 puffer, and also a green spotted puffer in a 10 gal. But they were single inhabitants. I'm sure they would eat the crab as they like shellfish and live food.

[penpitt]

Figure 8 puffers require at least 15 gallons and the GSP requires at least 30 gallons so both of those would be out of the question. Dwarf puffers are a FW species and will not fare well in a BW setup. a BB goby might be an option but I have no idea how it would do with a crab. Another option might be some ghost shrimp since I believe they are BW adaptable.